| blob | 1f155d399d576859ab502f0149bf2032285f3e49 |
1 /*
2 * Kernel execution entry point code.
3 *
4 * Copyright (c) 1995-1996 Gary Thomas <gdt@linuxppc.org>
5 * Initial PowerPC version.
6 * Copyright (c) 1996 Cort Dougan <cort@cs.nmt.edu>
7 * Rewritten for PReP
8 * Copyright (c) 1996 Paul Mackerras <paulus@cs.anu.edu.au>
9 * Low-level exception handers, MMU support, and rewrite.
10 * Copyright (c) 1997 Dan Malek <dmalek@jlc.net>
11 * PowerPC 8xx modifications.
12 * Copyright (c) 1998-1999 TiVo, Inc.
13 * PowerPC 403GCX modifications.
14 * Copyright (c) 1999 Grant Erickson <grant@lcse.umn.edu>
15 * PowerPC 403GCX/405GP modifications.
16 * Copyright 2000 MontaVista Software Inc.
17 * PPC405 modifications
18 * PowerPC 403GCX/405GP modifications.
19 * Author: MontaVista Software, Inc.
20 * frank_rowand@mvista.com or source@mvista.com
21 * debbie_chu@mvista.com
22 * Copyright 2002-2004 MontaVista Software, Inc.
23 * PowerPC 44x support, Matt Porter <mporter@kernel.crashing.org>
24 * Copyright 2004 Freescale Semiconductor, Inc
25 * PowerPC e500 modifications, Kumar Gala <galak@kernel.crashing.org>
26 *
27 * This program is free software; you can redistribute it and/or modify it
28 * under the terms of the GNU General Public License as published by the
29 * Free Software Foundation; either version 2 of the License, or (at your
30 * option) any later version.
31 */
33 #include <linux/threads.h>
34 #include <asm/processor.h>
35 #include <asm/page.h>
36 #include <asm/mmu.h>
37 #include <asm/pgtable.h>
38 #include <asm/cputable.h>
39 #include <asm/thread_info.h>
40 #include <asm/ppc_asm.h>
41 #include <asm/asm-offsets.h>
42 #include "head_booke.h"
44 /* As with the other PowerPC ports, it is expected that when code
45 * execution begins here, the following registers contain valid, yet
46 * optional, information:
47 *
48 * r3 - Board info structure pointer (DRAM, frequency, MAC address, etc.)
49 * r4 - Starting address of the init RAM disk
50 * r5 - Ending address of the init RAM disk
51 * r6 - Start of kernel command line string (e.g. "mem=128")
52 * r7 - End of kernel command line string
53 *
54 */
55 .text
56 _GLOBAL(_stext)
57 _GLOBAL(_start)
58 /*
59 * Reserve a word at a fixed location to store the address
60 * of abatron_pteptrs
61 */
62 nop
63 /*
64 * Save parameters we are passed
65 */
66 mr r31,r3
67 mr r30,r4
68 mr r29,r5
69 mr r28,r6
70 mr r27,r7
71 li r24,0 /* CPU number */
73 /* We try to not make any assumptions about how the boot loader
74 * setup or used the TLBs. We invalidate all mappings from the
75 * boot loader and load a single entry in TLB1[0] to map the
76 * first 16M of kernel memory. Any boot info passed from the
77 * bootloader needs to live in this first 16M.
78 *
79 * Requirement on bootloader:
80 * - The page we're executing in needs to reside in TLB1 and
81 * have IPROT=1. If not an invalidate broadcast could
82 * evict the entry we're currently executing in.
83 *
84 * r3 = Index of TLB1 were executing in
85 * r4 = Current MSR[IS]
86 * r5 = Index of TLB1 temp mapping
87 *
88 * Later in mapin_ram we will correctly map lowmem, and resize TLB1[0]
89 * if needed
90 */
92 /* 1. Find the index of the entry we're executing in */
93 bl invstr /* Find our address */
94 invstr: mflr r6 /* Make it accessible */
95 mfmsr r7
96 rlwinm r4,r7,27,31,31 /* extract MSR[IS] */
97 mfspr r7, SPRN_PID0
98 slwi r7,r7,16
99 or r7,r7,r4
100 mtspr SPRN_MAS6,r7
101 tlbsx 0,r6 /* search MSR[IS], SPID=PID0 */
102 #ifndef CONFIG_E200
103 mfspr r7,SPRN_MAS1
104 andis. r7,r7,MAS1_VALID@h
105 bne match_TLB
106 mfspr r7,SPRN_PID1
107 slwi r7,r7,16
108 or r7,r7,r4
109 mtspr SPRN_MAS6,r7
110 tlbsx 0,r6 /* search MSR[IS], SPID=PID1 */
111 mfspr r7,SPRN_MAS1
112 andis. r7,r7,MAS1_VALID@h
113 bne match_TLB
114 mfspr r7, SPRN_PID2
115 slwi r7,r7,16
116 or r7,r7,r4
117 mtspr SPRN_MAS6,r7
118 tlbsx 0,r6 /* Fall through, we had to match */
119 #endif
120 match_TLB:
121 mfspr r7,SPRN_MAS0
122 rlwinm r3,r7,16,20,31 /* Extract MAS0(Entry) */
124 mfspr r7,SPRN_MAS1 /* Insure IPROT set */
125 oris r7,r7,MAS1_IPROT@h
126 mtspr SPRN_MAS1,r7
127 tlbwe
129 /* 2. Invalidate all entries except the entry we're executing in */
130 mfspr r9,SPRN_TLB1CFG
131 andi. r9,r9,0xfff
132 li r6,0 /* Set Entry counter to 0 */
133 1: lis r7,0x1000 /* Set MAS0(TLBSEL) = 1 */
134 rlwimi r7,r6,16,4,15 /* Setup MAS0 = TLBSEL | ESEL(r6) */
135 mtspr SPRN_MAS0,r7
136 tlbre
137 mfspr r7,SPRN_MAS1
138 rlwinm r7,r7,0,2,31 /* Clear MAS1 Valid and IPROT */
139 cmpw r3,r6
140 beq skpinv /* Dont update the current execution TLB */
141 mtspr SPRN_MAS1,r7
142 tlbwe
143 isync
144 skpinv: addi r6,r6,1 /* Increment */
145 cmpw r6,r9 /* Are we done? */
146 bne 1b /* If not, repeat */
148 /* Invalidate TLB0 */
149 li r6,0x04
150 tlbivax 0,r6
151 #ifdef CONFIG_SMP
152 tlbsync
153 #endif
154 /* Invalidate TLB1 */
155 li r6,0x0c
156 tlbivax 0,r6
157 #ifdef CONFIG_SMP
158 tlbsync
159 #endif
160 msync
162 /* 3. Setup a temp mapping and jump to it */
163 andi. r5, r3, 0x1 /* Find an entry not used and is non-zero */
164 addi r5, r5, 0x1
165 lis r7,0x1000 /* Set MAS0(TLBSEL) = 1 */
166 rlwimi r7,r3,16,4,15 /* Setup MAS0 = TLBSEL | ESEL(r3) */
167 mtspr SPRN_MAS0,r7
168 tlbre
170 /* Just modify the entry ID and EPN for the temp mapping */
171 lis r7,0x1000 /* Set MAS0(TLBSEL) = 1 */
172 rlwimi r7,r5,16,4,15 /* Setup MAS0 = TLBSEL | ESEL(r5) */
173 mtspr SPRN_MAS0,r7
174 xori r6,r4,1 /* Setup TMP mapping in the other Address space */
175 slwi r6,r6,12
176 oris r6,r6,(MAS1_VALID|MAS1_IPROT)@h
177 ori r6,r6,(MAS1_TSIZE(BOOKE_PAGESZ_4K))@l
178 mtspr SPRN_MAS1,r6
179 mfspr r6,SPRN_MAS2
180 li r7,0 /* temp EPN = 0 */
181 rlwimi r7,r6,0,20,31
182 mtspr SPRN_MAS2,r7
183 tlbwe
185 xori r6,r4,1
186 slwi r6,r6,5 /* setup new context with other address space */
187 bl 1f /* Find our address */
188 1: mflr r9
189 rlwimi r7,r9,0,20,31
190 addi r7,r7,24
191 mtspr SPRN_SRR0,r7
192 mtspr SPRN_SRR1,r6
193 rfi
195 /* 4. Clear out PIDs & Search info */
196 li r6,0
197 mtspr SPRN_PID0,r6
198 #ifndef CONFIG_E200
199 mtspr SPRN_PID1,r6
200 mtspr SPRN_PID2,r6
201 #endif
202 mtspr SPRN_MAS6,r6
204 /* 5. Invalidate mapping we started in */
205 lis r7,0x1000 /* Set MAS0(TLBSEL) = 1 */
206 rlwimi r7,r3,16,4,15 /* Setup MAS0 = TLBSEL | ESEL(r3) */
207 mtspr SPRN_MAS0,r7
208 tlbre
209 mfspr r6,SPRN_MAS1
210 rlwinm r6,r6,0,2,0 /* clear IPROT */
211 mtspr SPRN_MAS1,r6
212 tlbwe
213 /* Invalidate TLB1 */
214 li r9,0x0c
215 tlbivax 0,r9
216 #ifdef CONFIG_SMP
217 tlbsync
218 #endif
219 msync
221 /* 6. Setup KERNELBASE mapping in TLB1[0] */
222 lis r6,0x1000 /* Set MAS0(TLBSEL) = TLB1(1), ESEL = 0 */
223 mtspr SPRN_MAS0,r6
224 lis r6,(MAS1_VALID|MAS1_IPROT)@h
225 ori r6,r6,(MAS1_TSIZE(BOOKE_PAGESZ_16M))@l
226 mtspr SPRN_MAS1,r6
227 li r7,0
228 lis r6,KERNELBASE@h
229 ori r6,r6,KERNELBASE@l
230 rlwimi r6,r7,0,20,31
231 mtspr SPRN_MAS2,r6
232 li r7,(MAS3_SX|MAS3_SW|MAS3_SR)
233 mtspr SPRN_MAS3,r7
234 tlbwe
236 /* 7. Jump to KERNELBASE mapping */
237 lis r7,MSR_KERNEL@h
238 ori r7,r7,MSR_KERNEL@l
239 bl 1f /* Find our address */
240 1: mflr r9
241 rlwimi r6,r9,0,20,31
242 addi r6,r6,24
243 mtspr SPRN_SRR0,r6
244 mtspr SPRN_SRR1,r7
245 rfi /* start execution out of TLB1[0] entry */
247 /* 8. Clear out the temp mapping */
248 lis r7,0x1000 /* Set MAS0(TLBSEL) = 1 */
249 rlwimi r7,r5,16,4,15 /* Setup MAS0 = TLBSEL | ESEL(r5) */
250 mtspr SPRN_MAS0,r7
251 tlbre
252 mfspr r8,SPRN_MAS1
253 rlwinm r8,r8,0,2,0 /* clear IPROT */
254 mtspr SPRN_MAS1,r8
255 tlbwe
256 /* Invalidate TLB1 */
257 li r9,0x0c
258 tlbivax 0,r9
259 #ifdef CONFIG_SMP
260 tlbsync
261 #endif
262 msync
264 /* Establish the interrupt vector offsets */
265 SET_IVOR(0, CriticalInput);
266 SET_IVOR(1, MachineCheck);
267 SET_IVOR(2, DataStorage);
268 SET_IVOR(3, InstructionStorage);
269 SET_IVOR(4, ExternalInput);
270 SET_IVOR(5, Alignment);
271 SET_IVOR(6, Program);
272 SET_IVOR(7, FloatingPointUnavailable);
273 SET_IVOR(8, SystemCall);
274 SET_IVOR(9, AuxillaryProcessorUnavailable);
275 SET_IVOR(10, Decrementer);
276 SET_IVOR(11, FixedIntervalTimer);
277 SET_IVOR(12, WatchdogTimer);
278 SET_IVOR(13, DataTLBError);
279 SET_IVOR(14, InstructionTLBError);
280 SET_IVOR(15, Debug);
281 SET_IVOR(32, SPEUnavailable);
282 SET_IVOR(33, SPEFloatingPointData);
283 SET_IVOR(34, SPEFloatingPointRound);
284 #ifndef CONFIG_E200
285 SET_IVOR(35, PerformanceMonitor);
286 #endif
288 /* Establish the interrupt vector base */
289 lis r4,interrupt_base@h /* IVPR only uses the high 16-bits */
290 mtspr SPRN_IVPR,r4
292 /* Setup the defaults for TLB entries */
293 li r2,(MAS4_TSIZED(BOOKE_PAGESZ_4K))@l
294 #ifdef CONFIG_E200
295 oris r2,r2,MAS4_TLBSELD(1)@h
296 #endif
297 mtspr SPRN_MAS4, r2
299 #if 0
300 /* Enable DOZE */
301 mfspr r2,SPRN_HID0
302 oris r2,r2,HID0_DOZE@h
303 mtspr SPRN_HID0, r2
304 #endif
305 #ifdef CONFIG_E200
306 /* enable dedicated debug exception handling resources (Debug APU) */
307 mfspr r2,SPRN_HID0
308 ori r2,r2,HID0_DAPUEN@l
309 mtspr SPRN_HID0,r2
310 #endif
312 #if !defined(CONFIG_BDI_SWITCH)
313 /*
314 * The Abatron BDI JTAG debugger does not tolerate others
315 * mucking with the debug registers.
316 */
317 lis r2,DBCR0_IDM@h
318 mtspr SPRN_DBCR0,r2
319 isync
320 /* clear any residual debug events */
321 li r2,-1
322 mtspr SPRN_DBSR,r2
323 #endif
325 /*
326 * This is where the main kernel code starts.
327 */
329 /* ptr to current */
330 lis r2,init_task@h
331 ori r2,r2,init_task@l
333 /* ptr to current thread */
334 addi r4,r2,THREAD /* init task's THREAD */
335 mtspr SPRN_SPRG3,r4
337 /* stack */
338 lis r1,init_thread_union@h
339 ori r1,r1,init_thread_union@l
340 li r0,0
341 stwu r0,THREAD_SIZE-STACK_FRAME_OVERHEAD(r1)
343 bl early_init
345 mfspr r3,SPRN_TLB1CFG
346 andi. r3,r3,0xfff
347 lis r4,num_tlbcam_entries@ha
348 stw r3,num_tlbcam_entries@l(r4)
349 /*
350 * Decide what sort of machine this is and initialize the MMU.
351 */
352 mr r3,r31
353 mr r4,r30
354 mr r5,r29
355 mr r6,r28
356 mr r7,r27
357 bl machine_init
358 bl MMU_init
360 /* Setup PTE pointers for the Abatron bdiGDB */
361 lis r6, swapper_pg_dir@h
362 ori r6, r6, swapper_pg_dir@l
363 lis r5, abatron_pteptrs@h
364 ori r5, r5, abatron_pteptrs@l
365 lis r4, KERNELBASE@h
366 ori r4, r4, KERNELBASE@l
367 stw r5, 0(r4) /* Save abatron_pteptrs at a fixed location */
368 stw r6, 0(r5)
370 /* Let's move on */
371 lis r4,start_kernel@h
372 ori r4,r4,start_kernel@l
373 lis r3,MSR_KERNEL@h
374 ori r3,r3,MSR_KERNEL@l
375 mtspr SPRN_SRR0,r4
376 mtspr SPRN_SRR1,r3
377 rfi /* change context and jump to start_kernel */
379 /* Macros to hide the PTE size differences
380 *
381 * FIND_PTE -- walks the page tables given EA & pgdir pointer
382 * r10 -- EA of fault
383 * r11 -- PGDIR pointer
384 * r12 -- free
385 * label 2: is the bailout case
386 *
387 * if we find the pte (fall through):
388 * r11 is low pte word
389 * r12 is pointer to the pte
390 */
391 #ifdef CONFIG_PTE_64BIT
392 #define PTE_FLAGS_OFFSET 4
393 #define FIND_PTE \
394 rlwinm r12, r10, 13, 19, 29; /* Compute pgdir/pmd offset */ \
395 lwzx r11, r12, r11; /* Get pgd/pmd entry */ \
396 rlwinm. r12, r11, 0, 0, 20; /* Extract pt base address */ \
397 beq 2f; /* Bail if no table */ \
398 rlwimi r12, r10, 23, 20, 28; /* Compute pte address */ \
399 lwz r11, 4(r12); /* Get pte entry */
400 #else
401 #define PTE_FLAGS_OFFSET 0
402 #define FIND_PTE \
403 rlwimi r11, r10, 12, 20, 29; /* Create L1 (pgdir/pmd) address */ \
404 lwz r11, 0(r11); /* Get L1 entry */ \
405 rlwinm. r12, r11, 0, 0, 19; /* Extract L2 (pte) base address */ \
406 beq 2f; /* Bail if no table */ \
407 rlwimi r12, r10, 22, 20, 29; /* Compute PTE address */ \
408 lwz r11, 0(r12); /* Get Linux PTE */
409 #endif
411 /*
412 * Interrupt vector entry code
413 *
414 * The Book E MMUs are always on so we don't need to handle
415 * interrupts in real mode as with previous PPC processors. In
416 * this case we handle interrupts in the kernel virtual address
417 * space.
418 *
419 * Interrupt vectors are dynamically placed relative to the
420 * interrupt prefix as determined by the address of interrupt_base.
421 * The interrupt vectors offsets are programmed using the labels
422 * for each interrupt vector entry.
423 *
424 * Interrupt vectors must be aligned on a 16 byte boundary.
425 * We align on a 32 byte cache line boundary for good measure.
426 */
428 interrupt_base:
429 /* Critical Input Interrupt */
430 CRITICAL_EXCEPTION(0x0100, CriticalInput, unknown_exception)
432 /* Machine Check Interrupt */
433 #ifdef CONFIG_E200
434 /* no RFMCI, MCSRRs on E200 */
435 CRITICAL_EXCEPTION(0x0200, MachineCheck, machine_check_exception)
436 #else
437 MCHECK_EXCEPTION(0x0200, MachineCheck, machine_check_exception)
438 #endif
440 /* Data Storage Interrupt */
441 START_EXCEPTION(DataStorage)
442 mtspr SPRN_SPRG0, r10 /* Save some working registers */
443 mtspr SPRN_SPRG1, r11
444 mtspr SPRN_SPRG4W, r12
445 mtspr SPRN_SPRG5W, r13
446 mfcr r11
447 mtspr SPRN_SPRG7W, r11
449 /*
450 * Check if it was a store fault, if not then bail
451 * because a user tried to access a kernel or
452 * read-protected page. Otherwise, get the
453 * offending address and handle it.
454 */
455 mfspr r10, SPRN_ESR
456 andis. r10, r10, ESR_ST@h
457 beq 2f
459 mfspr r10, SPRN_DEAR /* Get faulting address */
461 /* If we are faulting a kernel address, we have to use the
462 * kernel page tables.
463 */
464 lis r11, TASK_SIZE@h
465 ori r11, r11, TASK_SIZE@l
466 cmplw 0, r10, r11
467 bge 2f
469 /* Get the PGD for the current thread */
470 3:
471 mfspr r11,SPRN_SPRG3
472 lwz r11,PGDIR(r11)
473 4:
474 FIND_PTE
476 /* Are _PAGE_USER & _PAGE_RW set & _PAGE_HWWRITE not? */
477 andi. r13, r11, _PAGE_RW|_PAGE_USER|_PAGE_HWWRITE
478 cmpwi 0, r13, _PAGE_RW|_PAGE_USER
479 bne 2f /* Bail if not */
481 /* Update 'changed'. */
482 ori r11, r11, _PAGE_DIRTY|_PAGE_ACCESSED|_PAGE_HWWRITE
483 stw r11, PTE_FLAGS_OFFSET(r12) /* Update Linux page table */
485 /* MAS2 not updated as the entry does exist in the tlb, this
486 fault taken to detect state transition (eg: COW -> DIRTY)
487 */
488 andi. r11, r11, _PAGE_HWEXEC
489 rlwimi r11, r11, 31, 27, 27 /* SX <- _PAGE_HWEXEC */
490 ori r11, r11, (MAS3_UW|MAS3_SW|MAS3_UR|MAS3_SR)@l /* set static perms */
492 /* update search PID in MAS6, AS = 0 */
493 mfspr r12, SPRN_PID0
494 slwi r12, r12, 16
495 mtspr SPRN_MAS6, r12
497 /* find the TLB index that caused the fault. It has to be here. */
498 tlbsx 0, r10
500 /* only update the perm bits, assume the RPN is fine */
501 mfspr r12, SPRN_MAS3
502 rlwimi r12, r11, 0, 20, 31
503 mtspr SPRN_MAS3,r12
504 tlbwe
506 /* Done...restore registers and get out of here. */
507 mfspr r11, SPRN_SPRG7R
508 mtcr r11
509 mfspr r13, SPRN_SPRG5R
510 mfspr r12, SPRN_SPRG4R
511 mfspr r11, SPRN_SPRG1
512 mfspr r10, SPRN_SPRG0
513 rfi /* Force context change */
515 2:
516 /*
517 * The bailout. Restore registers to pre-exception conditions
518 * and call the heavyweights to help us out.
519 */
520 mfspr r11, SPRN_SPRG7R
521 mtcr r11
522 mfspr r13, SPRN_SPRG5R
523 mfspr r12, SPRN_SPRG4R
524 mfspr r11, SPRN_SPRG1
525 mfspr r10, SPRN_SPRG0
526 b data_access
528 /* Instruction Storage Interrupt */
529 INSTRUCTION_STORAGE_EXCEPTION
531 /* External Input Interrupt */
532 EXCEPTION(0x0500, ExternalInput, do_IRQ, EXC_XFER_LITE)
534 /* Alignment Interrupt */
535 ALIGNMENT_EXCEPTION
537 /* Program Interrupt */
538 PROGRAM_EXCEPTION
540 /* Floating Point Unavailable Interrupt */
541 #ifdef CONFIG_PPC_FPU
542 FP_UNAVAILABLE_EXCEPTION
543 #else
544 #ifdef CONFIG_E200
545 /* E200 treats 'normal' floating point instructions as FP Unavail exception */
546 EXCEPTION(0x0800, FloatingPointUnavailable, program_check_exception, EXC_XFER_EE)
547 #else
548 EXCEPTION(0x0800, FloatingPointUnavailable, unknown_exception, EXC_XFER_EE)
549 #endif
550 #endif
552 /* System Call Interrupt */
553 START_EXCEPTION(SystemCall)
554 NORMAL_EXCEPTION_PROLOG
555 EXC_XFER_EE_LITE(0x0c00, DoSyscall)
557 /* Auxillary Processor Unavailable Interrupt */
558 EXCEPTION(0x2900, AuxillaryProcessorUnavailable, unknown_exception, EXC_XFER_EE)
560 /* Decrementer Interrupt */
561 DECREMENTER_EXCEPTION
563 /* Fixed Internal Timer Interrupt */
564 /* TODO: Add FIT support */
565 EXCEPTION(0x3100, FixedIntervalTimer, unknown_exception, EXC_XFER_EE)
567 /* Watchdog Timer Interrupt */
568 #ifdef CONFIG_BOOKE_WDT
569 CRITICAL_EXCEPTION(0x3200, WatchdogTimer, WatchdogException)
570 #else
571 CRITICAL_EXCEPTION(0x3200, WatchdogTimer, unknown_exception)
572 #endif
574 /* Data TLB Error Interrupt */
575 START_EXCEPTION(DataTLBError)
576 mtspr SPRN_SPRG0, r10 /* Save some working registers */
577 mtspr SPRN_SPRG1, r11
578 mtspr SPRN_SPRG4W, r12
579 mtspr SPRN_SPRG5W, r13
580 mfcr r11
581 mtspr SPRN_SPRG7W, r11
582 mfspr r10, SPRN_DEAR /* Get faulting address */
584 /* If we are faulting a kernel address, we have to use the
585 * kernel page tables.
586 */
587 lis r11, TASK_SIZE@h
588 ori r11, r11, TASK_SIZE@l
589 cmplw 5, r10, r11
590 blt 5, 3f
591 lis r11, swapper_pg_dir@h
592 ori r11, r11, swapper_pg_dir@l
594 mfspr r12,SPRN_MAS1 /* Set TID to 0 */
595 rlwinm r12,r12,0,16,1
596 mtspr SPRN_MAS1,r12
598 b 4f
600 /* Get the PGD for the current thread */
601 3:
602 mfspr r11,SPRN_SPRG3
603 lwz r11,PGDIR(r11)
605 4:
606 FIND_PTE
607 andi. r13, r11, _PAGE_PRESENT /* Is the page present? */
608 beq 2f /* Bail if not present */
610 #ifdef CONFIG_PTE_64BIT
611 lwz r13, 0(r12)
612 #endif
613 ori r11, r11, _PAGE_ACCESSED
614 stw r11, PTE_FLAGS_OFFSET(r12)
616 /* Jump to common tlb load */
617 b finish_tlb_load
618 2:
619 /* The bailout. Restore registers to pre-exception conditions
620 * and call the heavyweights to help us out.
621 */
622 mfspr r11, SPRN_SPRG7R
623 mtcr r11
624 mfspr r13, SPRN_SPRG5R
625 mfspr r12, SPRN_SPRG4R
626 mfspr r11, SPRN_SPRG1
627 mfspr r10, SPRN_SPRG0
628 b data_access
630 /* Instruction TLB Error Interrupt */
631 /*
632 * Nearly the same as above, except we get our
633 * information from different registers and bailout
634 * to a different point.
635 */
636 START_EXCEPTION(InstructionTLBError)
637 mtspr SPRN_SPRG0, r10 /* Save some working registers */
638 mtspr SPRN_SPRG1, r11
639 mtspr SPRN_SPRG4W, r12
640 mtspr SPRN_SPRG5W, r13
641 mfcr r11
642 mtspr SPRN_SPRG7W, r11
643 mfspr r10, SPRN_SRR0 /* Get faulting address */
645 /* If we are faulting a kernel address, we have to use the
646 * kernel page tables.
647 */
648 lis r11, TASK_SIZE@h
649 ori r11, r11, TASK_SIZE@l
650 cmplw 5, r10, r11
651 blt 5, 3f
652 lis r11, swapper_pg_dir@h
653 ori r11, r11, swapper_pg_dir@l
655 mfspr r12,SPRN_MAS1 /* Set TID to 0 */
656 rlwinm r12,r12,0,16,1
657 mtspr SPRN_MAS1,r12
659 b 4f
661 /* Get the PGD for the current thread */
662 3:
663 mfspr r11,SPRN_SPRG3
664 lwz r11,PGDIR(r11)
666 4:
667 FIND_PTE
668 andi. r13, r11, _PAGE_PRESENT /* Is the page present? */
669 beq 2f /* Bail if not present */
671 #ifdef CONFIG_PTE_64BIT
672 lwz r13, 0(r12)
673 #endif
674 ori r11, r11, _PAGE_ACCESSED
675 stw r11, PTE_FLAGS_OFFSET(r12)
677 /* Jump to common TLB load point */
678 b finish_tlb_load
680 2:
681 /* The bailout. Restore registers to pre-exception conditions
682 * and call the heavyweights to help us out.
683 */
684 mfspr r11, SPRN_SPRG7R
685 mtcr r11
686 mfspr r13, SPRN_SPRG5R
687 mfspr r12, SPRN_SPRG4R
688 mfspr r11, SPRN_SPRG1
689 mfspr r10, SPRN_SPRG0
690 b InstructionStorage
692 #ifdef CONFIG_SPE
693 /* SPE Unavailable */
694 START_EXCEPTION(SPEUnavailable)
695 NORMAL_EXCEPTION_PROLOG
696 bne load_up_spe
697 addi r3,r1,STACK_FRAME_OVERHEAD
698 EXC_XFER_EE_LITE(0x2010, KernelSPE)
699 #else
700 EXCEPTION(0x2020, SPEUnavailable, unknown_exception, EXC_XFER_EE)
701 #endif /* CONFIG_SPE */
703 /* SPE Floating Point Data */
704 #ifdef CONFIG_SPE
705 EXCEPTION(0x2030, SPEFloatingPointData, SPEFloatingPointException, EXC_XFER_EE);
706 #else
707 EXCEPTION(0x2040, SPEFloatingPointData, unknown_exception, EXC_XFER_EE)
708 #endif /* CONFIG_SPE */
710 /* SPE Floating Point Round */
711 EXCEPTION(0x2050, SPEFloatingPointRound, unknown_exception, EXC_XFER_EE)
713 /* Performance Monitor */
714 EXCEPTION(0x2060, PerformanceMonitor, performance_monitor_exception, EXC_XFER_STD)
717 /* Debug Interrupt */
718 DEBUG_EXCEPTION
720 /*
721 * Local functions
722 */
724 /*
725 * Data TLB exceptions will bail out to this point
726 * if they can't resolve the lightweight TLB fault.
727 */
728 data_access:
729 NORMAL_EXCEPTION_PROLOG
730 mfspr r5,SPRN_ESR /* Grab the ESR, save it, pass arg3 */
731 stw r5,_ESR(r11)
732 mfspr r4,SPRN_DEAR /* Grab the DEAR, save it, pass arg2 */
733 andis. r10,r5,(ESR_ILK|ESR_DLK)@h
734 bne 1f
735 EXC_XFER_EE_LITE(0x0300, handle_page_fault)
736 1:
737 addi r3,r1,STACK_FRAME_OVERHEAD
738 EXC_XFER_EE_LITE(0x0300, CacheLockingException)
740 /*
742 * Both the instruction and data TLB miss get to this
743 * point to load the TLB.
744 * r10 - EA of fault
745 * r11 - TLB (info from Linux PTE)
746 * r12, r13 - available to use
747 * CR5 - results of addr < TASK_SIZE
748 * MAS0, MAS1 - loaded with proper value when we get here
749 * MAS2, MAS3 - will need additional info from Linux PTE
750 * Upon exit, we reload everything and RFI.
751 */
752 finish_tlb_load:
753 /*
754 * We set execute, because we don't have the granularity to
755 * properly set this at the page level (Linux problem).
756 * Many of these bits are software only. Bits we don't set
757 * here we (properly should) assume have the appropriate value.
758 */
760 mfspr r12, SPRN_MAS2
761 #ifdef CONFIG_PTE_64BIT
762 rlwimi r12, r11, 26, 24, 31 /* extract ...WIMGE from pte */
763 #else
764 rlwimi r12, r11, 26, 27, 31 /* extract WIMGE from pte */
765 #endif
766 mtspr SPRN_MAS2, r12
768 bge 5, 1f
770 /* is user addr */
771 andi. r12, r11, (_PAGE_USER | _PAGE_HWWRITE | _PAGE_HWEXEC)
772 andi. r10, r11, _PAGE_USER /* Test for _PAGE_USER */
773 srwi r10, r12, 1
774 or r12, r12, r10 /* Copy user perms into supervisor */
775 iseleq r12, 0, r12
776 b 2f
778 /* is kernel addr */
779 1: rlwinm r12, r11, 31, 29, 29 /* Extract _PAGE_HWWRITE into SW */
780 ori r12, r12, (MAS3_SX | MAS3_SR)
782 #ifdef CONFIG_PTE_64BIT
783 2: rlwimi r12, r13, 24, 0, 7 /* grab RPN[32:39] */
784 rlwimi r12, r11, 24, 8, 19 /* grab RPN[40:51] */
785 mtspr SPRN_MAS3, r12
786 BEGIN_FTR_SECTION
787 srwi r10, r13, 8 /* grab RPN[8:31] */
788 mtspr SPRN_MAS7, r10
789 END_FTR_SECTION_IFSET(CPU_FTR_BIG_PHYS)
790 #else
791 2: rlwimi r11, r12, 0, 20, 31 /* Extract RPN from PTE and merge with perms */
792 mtspr SPRN_MAS3, r11
793 #endif
794 #ifdef CONFIG_E200
795 /* Round robin TLB1 entries assignment */
796 mfspr r12, SPRN_MAS0
798 /* Extract TLB1CFG(NENTRY) */
799 mfspr r11, SPRN_TLB1CFG
800 andi. r11, r11, 0xfff
802 /* Extract MAS0(NV) */
803 andi. r13, r12, 0xfff
804 addi r13, r13, 1
805 cmpw 0, r13, r11
806 addi r12, r12, 1
808 /* check if we need to wrap */
809 blt 7f
811 /* wrap back to first free tlbcam entry */
812 lis r13, tlbcam_index@ha
813 lwz r13, tlbcam_index@l(r13)
814 rlwimi r12, r13, 0, 20, 31
815 7:
816 mtspr SPRN_MAS0,r12
817 #endif /* CONFIG_E200 */
819 tlbwe
821 /* Done...restore registers and get out of here. */
822 mfspr r11, SPRN_SPRG7R
823 mtcr r11
824 mfspr r13, SPRN_SPRG5R
825 mfspr r12, SPRN_SPRG4R
826 mfspr r11, SPRN_SPRG1
827 mfspr r10, SPRN_SPRG0
828 rfi /* Force context change */
830 #ifdef CONFIG_SPE
831 /* Note that the SPE support is closely modeled after the AltiVec
832 * support. Changes to one are likely to be applicable to the
833 * other! */
834 load_up_spe:
835 /*
836 * Disable SPE for the task which had SPE previously,
837 * and save its SPE registers in its thread_struct.
838 * Enables SPE for use in the kernel on return.
839 * On SMP we know the SPE units are free, since we give it up every
840 * switch. -- Kumar
841 */
842 mfmsr r5
843 oris r5,r5,MSR_SPE@h
844 mtmsr r5 /* enable use of SPE now */
845 isync
846 /*
847 * For SMP, we don't do lazy SPE switching because it just gets too
848 * horrendously complex, especially when a task switches from one CPU
849 * to another. Instead we call giveup_spe in switch_to.
850 */
851 #ifndef CONFIG_SMP
852 lis r3,last_task_used_spe@ha
853 lwz r4,last_task_used_spe@l(r3)
854 cmpi 0,r4,0
855 beq 1f
856 addi r4,r4,THREAD /* want THREAD of last_task_used_spe */
857 SAVE_32EVRS(0,r10,r4)
858 evxor evr10, evr10, evr10 /* clear out evr10 */
859 evmwumiaa evr10, evr10, evr10 /* evr10 <- ACC = 0 * 0 + ACC */
860 li r5,THREAD_ACC
861 evstddx evr10, r4, r5 /* save off accumulator */
862 lwz r5,PT_REGS(r4)
863 lwz r4,_MSR-STACK_FRAME_OVERHEAD(r5)
864 lis r10,MSR_SPE@h
865 andc r4,r4,r10 /* disable SPE for previous task */
866 stw r4,_MSR-STACK_FRAME_OVERHEAD(r5)
867 1:
868 #endif /* CONFIG_SMP */
869 /* enable use of SPE after return */
870 oris r9,r9,MSR_SPE@h
871 mfspr r5,SPRN_SPRG3 /* current task's THREAD (phys) */
872 li r4,1
873 li r10,THREAD_ACC
874 stw r4,THREAD_USED_SPE(r5)
875 evlddx evr4,r10,r5
876 evmra evr4,evr4
877 REST_32EVRS(0,r10,r5)
878 #ifndef CONFIG_SMP
879 subi r4,r5,THREAD
880 stw r4,last_task_used_spe@l(r3)
881 #endif /* CONFIG_SMP */
882 /* restore registers and return */
883 2: REST_4GPRS(3, r11)
884 lwz r10,_CCR(r11)
885 REST_GPR(1, r11)
886 mtcr r10
887 lwz r10,_LINK(r11)
888 mtlr r10
889 REST_GPR(10, r11)
890 mtspr SPRN_SRR1,r9
891 mtspr SPRN_SRR0,r12
892 REST_GPR(9, r11)
893 REST_GPR(12, r11)
894 lwz r11,GPR11(r11)
895 rfi
897 /*
898 * SPE unavailable trap from kernel - print a message, but let
899 * the task use SPE in the kernel until it returns to user mode.
900 */
901 KernelSPE:
902 lwz r3,_MSR(r1)
903 oris r3,r3,MSR_SPE@h
904 stw r3,_MSR(r1) /* enable use of SPE after return */
905 lis r3,87f@h
906 ori r3,r3,87f@l
907 mr r4,r2 /* current */
908 lwz r5,_NIP(r1)
909 bl printk
910 b ret_from_except
911 87: .string "SPE used in kernel (task=%p, pc=%x) \n"
912 .align 4,0
914 #endif /* CONFIG_SPE */
916 /*
917 * Global functions
918 */
920 /*
921 * extern void loadcam_entry(unsigned int index)
922 *
923 * Load TLBCAM[index] entry in to the L2 CAM MMU
924 */
925 _GLOBAL(loadcam_entry)
926 lis r4,TLBCAM@ha
927 addi r4,r4,TLBCAM@l
928 mulli r5,r3,20
929 add r3,r5,r4
930 lwz r4,0(r3)
931 mtspr SPRN_MAS0,r4
932 lwz r4,4(r3)
933 mtspr SPRN_MAS1,r4
934 lwz r4,8(r3)
935 mtspr SPRN_MAS2,r4
936 lwz r4,12(r3)
937 mtspr SPRN_MAS3,r4
938 tlbwe
939 isync
940 blr
942 /*
943 * extern void giveup_altivec(struct task_struct *prev)
944 *
945 * The e500 core does not have an AltiVec unit.
946 */
947 _GLOBAL(giveup_altivec)
948 blr
950 #ifdef CONFIG_SPE
951 /*
952 * extern void giveup_spe(struct task_struct *prev)
953 *
954 */
955 _GLOBAL(giveup_spe)
956 mfmsr r5
957 oris r5,r5,MSR_SPE@h
958 mtmsr r5 /* enable use of SPE now */
959 isync
960 cmpi 0,r3,0
961 beqlr- /* if no previous owner, done */
962 addi r3,r3,THREAD /* want THREAD of task */
963 lwz r5,PT_REGS(r3)
964 cmpi 0,r5,0
965 SAVE_32EVRS(0, r4, r3)
966 evxor evr6, evr6, evr6 /* clear out evr6 */
967 evmwumiaa evr6, evr6, evr6 /* evr6 <- ACC = 0 * 0 + ACC */
968 li r4,THREAD_ACC
969 evstddx evr6, r4, r3 /* save off accumulator */
970 mfspr r6,SPRN_SPEFSCR
971 stw r6,THREAD_SPEFSCR(r3) /* save spefscr register value */
972 beq 1f
973 lwz r4,_MSR-STACK_FRAME_OVERHEAD(r5)
974 lis r3,MSR_SPE@h
975 andc r4,r4,r3 /* disable SPE for previous task */
976 stw r4,_MSR-STACK_FRAME_OVERHEAD(r5)
977 1:
978 #ifndef CONFIG_SMP
979 li r5,0
980 lis r4,last_task_used_spe@ha
981 stw r5,last_task_used_spe@l(r4)
982 #endif /* CONFIG_SMP */
983 blr
984 #endif /* CONFIG_SPE */
986 /*
987 * extern void giveup_fpu(struct task_struct *prev)
988 *
989 * Not all FSL Book-E cores have an FPU
990 */
991 #ifndef CONFIG_PPC_FPU
992 _GLOBAL(giveup_fpu)
993 blr
994 #endif
996 /*
997 * extern void abort(void)
998 *
999 * At present, this routine just applies a system reset.
1000 */
1001 _GLOBAL(abort)
1002 li r13,0
1003 mtspr SPRN_DBCR0,r13 /* disable all debug events */
1004 isync
1005 mfmsr r13
1006 ori r13,r13,MSR_DE@l /* Enable Debug Events */
1007 mtmsr r13
1008 isync
1009 mfspr r13,SPRN_DBCR0
1010 lis r13,(DBCR0_IDM|DBCR0_RST_CHIP)@h
1011 mtspr SPRN_DBCR0,r13
1012 isync
1014 _GLOBAL(set_context)
1016 #ifdef CONFIG_BDI_SWITCH
1017 /* Context switch the PTE pointer for the Abatron BDI2000.
1018 * The PGDIR is the second parameter.
1019 */
1020 lis r5, abatron_pteptrs@h
1021 ori r5, r5, abatron_pteptrs@l
1022 stw r4, 0x4(r5)
1023 #endif
1024 mtspr SPRN_PID,r3
1025 isync /* Force context change */
1026 blr
1028 /*
1029 * We put a few things here that have to be page-aligned. This stuff
1030 * goes at the beginning of the data segment, which is page-aligned.
1031 */
1032 .data
1033 .align 12
1034 .globl sdata
1035 sdata:
1036 .globl empty_zero_page
1037 empty_zero_page:
1038 .space 4096
1039 .globl swapper_pg_dir
1040 swapper_pg_dir:
1041 .space 4096
1043 /* Reserved 4k for the critical exception stack & 4k for the machine
1044 * check stack per CPU for kernel mode exceptions */
1045 .section .bss
1046 .align 12
1047 exception_stack_bottom:
1048 .space BOOKE_EXCEPTION_STACK_SIZE * NR_CPUS
1049 .globl exception_stack_top
1050 exception_stack_top:
1052 /*
1053 * This space gets a copy of optional info passed to us by the bootstrap
1054 * which is used to pass parameters into the kernel like root=/dev/sda1, etc.
1055 */
1056 .globl cmd_line
1057 cmd_line:
1058 .space 512
1060 /*
1061 * Room for two PTE pointers, usually the kernel and current user pointers
1062 * to their respective root page table.
1063 */
1064 abatron_pteptrs:
1065 .space 8